New mosquito virus present in Louisiana

BATON ROUGE, LA. – It has been about 12 years since West Nile virus, the mosquito-borne disease was, first identified in Louisiana, but this year the chikungunya fever has made its presence known.

The disease, which has been recognized in Asia and Africa for more than 60 years, was seen for the first time in the Western Hemisphere last December when it showed up in the Caribbean, said LSU AgCenter entomologist Kristen Healy.

“We know of eight cases of chikungunya fever so far in the state of Louisiana,” Healy said. “There has been one case in Grant Parish, three cases in Jefferson, three in Orleans and one in Tangipahoa.”

Each of the cases was imported into the state, Healy said. “Three were from Haiti and five from the Dominican Republic.”

Healy said the disease is spread from person to person by mosquito bites, but she assures that the disease is considered to be relatively mild when compared with other mosquito-borne diseases like malaria, dengue fever and yellow fever.

“Some people will have been infected with the virus but show no symptoms, as with West Nile virus,” Healy said. “Those who have symptoms will normally experience joint pain and fever, which can last as long as six to eight months.”

The disease is transmitted by female Asian Tiger mosquitoes taking a “blood meal”– a requirement in the insect’s reproductive process – from an infected person and transmitting it to another person, Healy said.

This is different from West Nile virus transmission, which is transmitted by mosquitoes first biting infected birds then biting humans.

In past years, about 20 imported cases of the disease were treated in the U. S. each year from people who have traveled to Asia or Africa and brought it back, she said.

The disease is unlikely to be fatal, but it is possible, she said. “This is especially true in the elderly, those who are seriously ill and newborns of infected mothers.”

There is no antivirus treatment available for chikungunya, Healy said. “Really, all that we can do right now is provide some relief for the symptoms.”

Healy said the public needs to do its part in controlling mosquitoes by making sure they are not providing a breeding ground by leaving standing water around.

This has been a good year for mosquitoes because of the large amount of rain in the state, she said.

“That is part of the problem, but we have to take some of the blame also,” Healy said. “Even I’m guilty of sometimes not getting rid of standing water around my home.”

You would be surprised at how the small amount of water held in a soft drink bottle cap left in a shaded area can serve as a breeding ground for mosquitoes, she said.